To suppress fires in enclosed structures such as residential attics or aircraft fuselages, as examples, the firefighter has the need to penetrate the structure with a nozzle through which he can inject fire extinguishing agents such as water or foam, or fire suppressant agents such as carbon dioxide, Halon, and AFFF. Fire extiguishing agents, and fire suppressant agents will for convenience be described herein merely as "agents". They will always be fluid--either a gas or a liquid, or a combination such as foam. There are, of course, time-honored procedures for doing this, some as simple as cutting a hole with an axe and shoving the nozzle through the opening.
This simplistic approach illuminates the many problems that are involved. One of the major problems is that the equipment is used under the most trying circumstances. By his very proximity to the fire, the firefighter is exposed to considerable danger. To reach the point of application of the tool he will already have gone through much exertion and anxiety. When he arrives at that point, to reduce his stress the tool should have had the least possible weight and have required the least possible physical exertion and care to get it there. Furthermore, the exertion that will be required to apply the tool to its task should not require the firefighter to assume risky or unbalanced postures.
While an axe might be a tool of most minimum weight, when the firefighter arrives he will have to take a hopefully balanced stance and make a number of strokes whose end result cannot accurately be guessed. If the axe goes on through the structure, for example, it could throw him off balance, and perhaps he will even lose the tool. Even if this is safely done, and it often is, there are two more concerns. The first concern is that if a hole of excessive size is cut, too much air can enter, and it can cause an explosive increase in the intensity of the fire and of its smoke. Such flare-ups, particularly in aircraft, have caused death and serious injury. The smaller the aperture for injection of suppressant agent, the better, and this is not best accomplished by swinging an axe at the structure.
Also, once the hole is cut, it is necessary to get a nozzle into it so the agent can be injected into the structure. If the firefighter wields an axe, and also is expected to insert the nozzle, he must discard the axe, grab the nozzle and insert it. This takes effort, and even if the nozzle is carried by another firefighter, it will take extra time. Extra time includes not only extra risk to the firefighter but additional property damage, and additional risk to occupants of the structure such as passengers in an aircraft fuselage.
Tools have been proposed and do exist which include rotary drill motors and bits to penetrate into structures, and which include nozzle means for injection of agents after penetration. One problem with such devices is their size, weight and bulkiness. Not only is the rig heavy because of the necessary drive mechanism for the drill, but power means such as bottled gas must be carried along to power it, or a power supplying hose must be brought along for power. Both of these expedients tire the firefighter.
It is an object of this invention to provide an elegantly simple penetrator which in its condition to be carried to its point of application has a minimum bulk and weight. Further, it carries as part of itself a slide hammer to exert penetrating blows on the structure through the tool body. The slide hammer slides on an integral guide rod which extends from the body of the tool only when blows are to be exerted. The tool thus can be retracted into a minimum bulk for carrying to its point of application. It can also be stored in a minimum space envelope.
When the blows are to be exerted, the hammer is constrained to an axial path, and requires no care by the firefighter. He simply cycles the hammer along the guide rod until the blows delivered by the tool causes the tool to penetrate the structure. Then an agent is injected into the penetrated structure through the tool. This is a simple, lightweight, reduced maintenance and trouble-free tool.